A cameraman for Al Jazeera was killed by a drone strike on Friday while reporting on the earlier bombing of a school used as a shelter for displaced people in the southern Gaza Strip, the Arabic broadcaster said.

Cameraman Samer Abu Daqqa was unable to get to safety or medical treatment after being injured in the strike on the Farhana School in Khan Younis and died of his wounds before ambulances were allowed in the area, Al Jazeera said.

Al Jazeera said Israeli drones fired missiles at the school. Reuters could not verify the details of the incident.

Israel's military did not respond to a request for comment.

"Following Samer's injury, he was left to bleed to death for over five hours, as Israeli forces prevented ambulances and rescue workers from reaching him, denying the much-needed emergency treatment," Al Jazeera said in a statement.

The journalists were reporting from the city in southern Gaza, which has been at the centre of Israel's ground offensive in recent days.

Three Gazan rescue workers were also killed in a strike on the school, said the Civil Defense department, part of the Hamas-controlled interior ministry. Reuters could not immediately establish the sequence of events.

Al Jazeera's chief correspondent Wael al-Dahdouh was injured in his hand in the attack but managed to reach a nearby hospital for treatment for his injuries, Al Jazeera said.

Dahdouh, a Gaza correspondent, is particularly well known to viewers across the Middle East after learning last month during an emotional live broadcast that his wife, son, daughter and grandson were killed in what the network said was an Israeli air strike.

The two months of war in Gaza have taken a heavy toll on journalists, with at least 64 reporters and media workers killed, the Committee to Protect Journalists said on Friday.

The CPJ called on international authorities to "conduct an independent investigation into the attack to hold the perpetrators to account."

Asked about the killing of Samer Abu Daqqa, White House national security spokesman John Kirby told reporters: "We still have no indications that the Israelis are deliberately going after journalists covering this war."